145 



of admiration, seems to exhibit nearly the complete form of the shells 

 of this genus. The particular figure of this fossil had heen, by most 

 of its observers, attributed to some changes which it had undergone 

 whilst in a soft mineralized state ; but I had been always satisfied 

 of its existing in its original shape, from reflecting on the improbability 

 of its spiral turns having been unfolded without fracture: a circum- 

 stance, indeed, which an examination of the specimen renders at once 

 evident. This curious fossil, which is formed of a blueish clay, was 

 found, as appears by a label, which is attached to it, in Shotover Hill, 

 near Oxford. 



LXXX. Scaphites. A fossil concamerated shell, commencing with 

 spiral turns ; the last of which, after being elongated, is reflected towards 

 the spiral part. 



I have ventured to form the present genus for the reception of the 

 very rare and interesting fossil, Plate X. Fig. 10, from Dorsetshire, 

 there being no genus in which it could be placed. 



This fossil is in a very excellent state of preservation : the nacre is 

 visible on some parts of it, and in others the foliaceous terminations of 

 the chambers may be discovered. At the termination of the reflected 

 part, the mouth of the shell, a border is formed, by the edge of a regu- 

 larly rounded groove, with which the shell appears to have been here 

 surrounded. 



The very wide difference between its form and that of the shells of 

 the genus Ammonites, to which it approaches the nearest, is sufficient, I 

 conceive, to show the propriety of a separation. I acknowledge that I 

 was at first disposed to consider it as a monstrosity ; supposing that the 

 animal had by some accident been misdirected in its operations of form- 

 ing its .shell, and had thereby been led to the formation of it in this 

 uncommon shape. A closer examination of the shell, however, set 

 aside this opinion ; for I then noticed the tubercles on the sides of the 

 straight part, which did not appear at all in the spiral, and but faintly 

 in the recurved part. This seemed to manifest that, at different pe- 



VOL. Ill, U 



